Internal-combustion engine



Feb. 19, 1929. 1,702,572

w. RIEHM INTERNAL COMBUSTION ENGINE Filed July 1. 1925 :Ci-JUE'HLUF )Yw MM MM M w 4d 1 fltzur'neys Patented Feb. 19, 1929.

UNITED STATES 1,702,572 PATENT OFFICE.

WILHELM BIEHM, OF AUGSBUBG, GERMANY, ASSIGNOR TO MASCHINENFABRIK AUGS- 'BURG-NUERNBERG, AKTIENGESELLSCHAFT, 0F AUGSBURG, GERMANY, A COR- V POBATION OF GERMANY.

INTERNAL-COMBUSTION ENGINE.

Application filed July 1, 1925, Serial No. 40,816, and in Germany July 12, 1924.

This invention relates to internal colnbusq tion engines and more particularly to doubleacting two stroke cycle combustion engines with ports for the scavenging agent, which are operated by injection of fuel without air.

In double-acting two-stroke combustion engines having ports cylinders and in which the injection of the fuel is accomplished without air, it is necessary to depart from the ordinary way of centrally injecting the fuel on the piston rod end of the cylinder and to arrange the fuel valves laterally of the piston rod, that is concentrically, in the cover or head of the cylinder. With this arrangement,however, it will be more diificult to have the combustion space fully under control, and the fuel will tend to more or less imperfectly mix with the combustion air thus affecting the quality of the combustion.

' In order to avoid this disadvantage and to facilitate the proper mixing of the injected fuel with the combustion air according'to this invention further'charging air is introduced into the end of the cylinder in which the piston rod is carried after closure of the intake and exhaust ports pertaining to said end of the cylinder,that is, after the completion of the scavenging and charging process in the said end of the cylinder, the introduction of said further charging air being accomplished by means of a controlling organ or member forming part of the valve mechanism of theengine in such a manner, that this air will be given a] circular on whirling motion. This air willithen also impart a circular orflwhirling motion to the combustion air, which otherwise upon the return stroke of the piston aftcr closure of the intake and exhaust ports would be essentially at rest. Thus the combustion air will be carried with the charging air and thereby the entire body of air in the cylinder will participate in this circular or whirling motion. If the fuel is injected into the air, which is kept in a cirular motion, it will completely mix with the same, so that each particle of the fuel will be in proximity to the quantity of air which is required for,:combustion.

The introduction of charging air after the scavenging and charging process proper i known in connection with two-stroke combustion engines, this subsequent introduction of charging air serving ior augmenting the for the scaven in of the uantity of air, which will raise the specific output of the engine. In the present case according to this invention this further charging air is introduced for the purpose of bringing about a circular motion of the air contained within the cylinder in order to secure a complete combustion of the fuel in the engine cylinders.

The accompanying drawing shows an example of carrying this invention into efi'ect in connection with the so-called. reversed scavenging process. In the drawing, Fig. 1 is a longitudinal section through a cylinder of a combustion engine constructed according to this invention and Fig. 2 is a crosssection through a cylinder in vertical direction to the cylinder-axis, said cross-section being taken along the line A-B of Fig. 1 in the direction indicated by the arrows. The cylinder is designated by the reference letter a, the piston by the reference letter I), said piston in the example as shown, being supposed to move towardthe lower dead point position. The piston rod is designated by the letter a. The scavenging air enters through the inlet ports d intothecylinder, said inlet ports being for instance so directed, that the divided currents of the scavenging air will move around the piston rod 0 and again join each other so as to form a single current mov- -ing toward the cylindercover in the space between piston rod and the closed cylin der wall. At this time the current will reverse its motion, again divide in two currents flowing around the piston rod; on the other side of the piston rod these two currents will again join each other and move towards the outlet ports. According to this invention there is provided a valve 7 for supplying the subsequent charging air through the cylinder cover e at the end of the cylinder which contains the piston rod, said valve 7 being opened upon the return stroke of the piston after closure of the inlet and exhaust ports, thus causing the said charging air to enter into the cylinder. The valve f is equipped with a screen or bafile g, which forces the charging air entering through the valve into a direction, which will cause a circular motion of the air within the combustion space in the direction indicated in Fig. 2 by the arrows h. The charging air ,will thus be mixed with the combustionair a circular motion to the entire combustion air contained in said end of the cylinder. In this manner the combustion air will be carried around to form an eddy, and the fuel is now injected into this eddy in the usual manner through the fuel valves '5, which may be employed in single or multiple arrangement. The fuel thus injected will now completely mix with the circularly moving combustion air.

The arrangement of the charging valve f together with the screen 9 provided thereon is supposed to represent only an example of a construction according to this invention, whereby the aforementioned circular motion or eddy of the combustion air is 'brought about. This circular motion may,

for instance, also be brought about by arranging the inlet channel for the subsequent charging air in such a direction in the cylinder cover, that the air will enter through [said channel into the combustion space in a direction, which is tangential or approximately tangential to thecylinder walls. The charging valve 7, instead of being mounted in the cylinder cover, may also be mounted in the wall of the cylinder. In this case the valve exhaust must again be so directed that the charging air will also enterthe combustion space in tangential or approximately a tangential direction, in order to bring about the above mentioned circular motion or eddy in the combustion air.

bustion engine of the character comprising a cylinder having scavenging I claim: 1. A double-acting two-stroke cycle comescri'bed,

a piston mounted within said cylinder con-.

trolling said scavenging air inlet and exhaust ports, a piston rod therefor, a cylinder cover carrying said piston rod, a valve for introducing subsequent charging airinto said cylinder adjacent the end thereof after closure of said scavenging air inlet and exhaust ports,

saidvalve having an outlet adapted to produce a circular motion of the charging air introduced therethrough to produce a circular motion of the air containedin the cylinder at its piston rod end. v v

3. An internal combustion engine of the character described, comprising a cylinder having scavenging air inlet and exhaust ports, a piston mounted within said cylinder, a charging valve for additional air operable independently of the piston and having means for directing the flow of air passing through said valve into the cylinder to cause circular motion of the air contained in said cylinder, and a fuel-injection valve for introducing fuel into said moving air;

4. An internal combustion engine of the character described, comprising a cylinder having scavenging air inlet and exhaust ports in the wall thereof, a piston in said cylinder controlling said ports, a valve op-- erable independently of the piston for introducing an extra charge of air into the cylinder in a manner to impart circular mo- 'ilOIltO the air within the cylinder, and a fuel-injection valve for introducing fuel into said moving air.

.5. An internal combustion engine of the character described comprising a cylinder having an air inlet port therein for admitting the main body of combustion air, and a secondary inlet port, for admitting additional air into the cylinder, said port having instrumentalities whereby the extra charge of air introduced through said port acts upon the air-within the cylinder to impart clrcular motion to the air within the cylinder.-

6. In the operation of an engine of the character described, the method which comprises introducing an extra charge of air in a circular motion into a main charge of combustion air to thereby also impart circular motion to the main charge of combustion air;

7. In the operation of'an engine of the character described, the method which comprises introducing a main charge of combustion air, compressing the charge, introducing during the compression an extra charge of air in a circular motion to thereby also-impart circular motion to the main charge of combustion air, and injecting fuel into the circulating body of compressed air.

In testimony whereof I my signature.

DR. WILHELM RIEHM.

have hereto aflixed 

